However, although Reinhart has attempted to become a champion for body positivity, her comments regarding Marilyn Monroe's "curvy" figure ignited backlash among some fans and trolls alike.

"She had boobs and she didn't have a 24-inch waist. To me that's really inspiring and makes me feel like my body can be accepted," Reinhart told Harper's Bazaar. (It may be important to note that Monroe was actually much slimmer than modern mythology portrays, with many outlets putting her waist measurement at around 22 inches.)

Critics pointed out that Reinhart already has a widely accepted — or, some may say, ideal — body type.

Some people even mocked Reinhart for "whining," while others chastised the 21-year-old for delivering "a slap in the face" to women whose bodies lack representation.

Reinhart in turn slammed these comments for contributing to the culture of body-shaming.

In a thread on Twitter, the actress encouraged fans to be more understanding of others' insecurities — regardless of how their bodies may be perceived.

The following day, Reinhart continued these thoughts with two additional tweets, admitting that she herself struggles with body dysmorphia.

"Feeling really disheartened by the fact that so many people are saying 'you're skinny so shut up about [embracing] your body.' As if my body dysmorphia is irrelevant because of how I look to some people," she wrote. "I'm either not curvy enough or not skinny enough to feel insecure."

" Mental illness gets worse when people say that you don't have a right to feel the way you do. That's where we are [failing]," she continued. "Do not encourage this behavior. It is destructive. More destructive than you'll ever realize. You may not understand someone's insecurity — but respect it."

Body dysmorphia is a dangerous and surprisingly common mental disorder.

"In reality, a perceived defect may be only a slight imperfection or nonexistent. But for someone with BDD, the flaw is significant and prominent, often causing severe emotional distress and difficulties in daily functioning," according to the ADAA website.

Mental health and body image often necessitate complicated and highly personal discussions, but the simple truth is that no one can know what goes on inside another person's head — and that expecting perfection from celebrities is a harmful and fruitless goal.